2 detained after gas canisters found near Paris' Notre Dame

FILE - In this March 27, 2016 file photo, a French Police officer stands guards as worshipers arrive for the Easter mass at Notre Dame Cathedral, in Paris. Police officials say Wednesday Sept. 7, 2016 a terrorism investigation is under way into seven gas canisters found in a car parked near Notre Dame Cathedral in Paris. The car was discovered Sunday morning along the Seine River, with no one inside and no license plates but with the hazard lights on, the officials said Wednesday (AP Photo/Francois Mori, File)
(The Associated Press)

FILE - In this March 27, 2016 file photo, a French Police officer stands guards as worshipers arrive for the Easter mass at Notre Dame Cathedral, in Paris. Police officials say Wednesday Sept. 7, 2016 a terrorism investigation is under way into seven gas canisters found in a car parked near Notre Dame Cathedral in Paris. The car was discovered Sunday morning along the Seine River, with no one inside and no license plates but with the hazard lights on, the officials said Wednesday (AP Photo/Francois Mori, File)
(The Associated Press)

PARIS – Police officials say a terrorism investigation is underway after a car parked near Notre Dame Cathedral in Paris was found with seven gas canisters inside.

Police said Wednesday that the car discovered Sunday morning along the Seine River with its hazard lights on had no license plates and no one inside. Six canisters filled with gas were found in the trunk and an empty one in the car.

An official says the couple that owned the car has been taken into custody.

France is on alert after a string of Islamic State attacks and threats against landmarks.

Gas canisters filled with nails were used in attacks on Paris in the 1990s by Algeria-linked extremists.